But chatgpt did not work very well. I start to find other ways to decompile it.
I found a project zh-explorer/mi_lua: xiaomi lua anti (github.com), this can convert mi luac to normal luac, then we can use many tools to decompile luac for the code.
This online tool Lua Decompiler (metaworm.site) worked very well!
The code decompiled by it is very clear to read.